Optically transparent polymeric actuator and display apparatus employing same

ABSTRACT

An optically transparent actuator apparatus is provided that includes an optically transparent bi-stable member including an optically transparent liquid crystalline polymer layer. The bi-stable member is structured to move from a first state to a second state in response to a first stimulus and from the second state to the first state in response to a second stimulus. Also, a display apparatus includes a plate member and an actuator assembly coupled to the plate member. The actuator assembly includes a number of optically transparent liquid crystalline polymer layers, wherein each of the optically transparent liquid crystalline polymer layers is structured to move from a first state to a second state in response to a first stimulus.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a U.S. National Stage Application under 35 U.S.C. §371 of PCT International Application No. PCT/US2017/036679, entitled“Optically Transparent Polymeric Actuator and Display ApparatusEmploying Same,” filed on Jun. 9, 2017, which claims priority under 35U.S.C. § 119(e) from U.S. provisional patent application No. 62/348,525,entitled “Optically Transparent Active Surfaces for Vivid Displays withHaptic Feedback,” filed on Jun. 10, 2016, the contents of which areincorporated herein by reference.

GOVERNMENT CONTRACT

This invention was made with government support under grant #1435489awarded by the National Science Foundation (NSF) and grant#FA9550-14-1-0229 awarded by the United States Air Force/Air ForceOffice of Scientific Research (USAF/AFOSR). The government has certainrights in the invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to actuator devices and displays thatemploy such devices, and, in particular, to an optically transparentpolymeric actuator and display devices employing same, such as displaydevices structured to provide haptic feedback and/or to deform toprovide three-dimensional (3D) structures as needed.

2. Description of the Related Art

Eliciting a programmed mechanical response to a non-mechanical stimulushas underpinned the development of shape memory materials in metals,ceramics and polymers. In low-density polymeric materials, the abilityto elicit shape changes in response to magnetic, electric, photonic andchemical stimulus holds implications for the fabrication of adaptivemachines with applications in the biomedical, electronics and defensesectors. In polymers, the shape memory can be stored via an array ofmolecular mechanisms including crystallization/vitrification incovalently cross-linked networks, by phase segregation in physicallycross-linked block copolymers, and by programming rigid molecularsegments in liquid crystalline polymers. Eliciting a memorized shape isoften pursued using heat and finds implementation in an array ofproducts involving heat-shrink polymers. In addition, a range of othertriggers have been examined, including electrical fields, magneticfields, UV, and IR irradiation.

A significant challenge in the development of active surfaces thatintegrate with wearable electronics and smart devices is the challengeof achieving the combination of broad wavelength optical transmission,mechanical adaptivity that is ultrafast, low energy consumption and theencapsulation of the structures in small form factors. This eliminates avast number of existing actuator technologies from being utilizedseamlessly in such applications.

SUMMARY OF THE INVENTION

In one embodiment, an optically transparent actuator apparatus isprovided that includes an optically transparent bi-stable memberincluding an optically transparent liquid crystalline polymer layer. Thebi-stable member is structured to move from a first state to a secondstate in response to a first stimulus and from the second state to thefirst state in response to a second stimulus.

In another embodiment, a method of controlling an actuator in a displayapparatus is provided. The method includes providing a first stimulus toan optically transparent bi-stable member including an opticallytransparent liquid crystalline polymer layer to cause the bi-stablemember to move from a first state to a second state, and providing asecond stimulus to the bi-stable member to cause the bi-stable member tomove from the second state to the first state.

In still another embodiment, a display apparatus is provided thatincludes a plate member and an actuator assembly coupled to the platemember. The actuator assembly includes a number of optically transparentliquid crystalline polymer layers, wherein each of the opticallytransparent liquid crystalline polymer layers is structured to move froma first state to a second state in response to a first stimulus.

In yet another embodiment, a method of making an optically transparentactuator element is provided. The method includes forming a firststructure including: (i) forming an optically transparent liquidcrystalline polymer layer, and (ii) forming a first opticallytransparent conductor member on a first surface of the opticallytransparent liquid crystalline polymer layer and a second opticallytransparent conductor member on a first surface of the opticallytransparent liquid crystalline polymer layer. The method furtherincludes applying a number of displacement forces to one or more ends ofthe first structure to cause the first structure to buckle and providean arch-shaped portion in the first structure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B show an optically transparent actuator element accordingto an exemplary embodiment of the disclosed concept;

FIG. 2 is a schematic diagram of a portion of an optically transparentactuator element according to the exemplary embodiment;

FIG. 3 is a schematic diagram of a twisted nematic liquid crystallinepolymer film employed in one embodiment of the disclosed concept;

FIG. 4 is a schematic diagram of a splayed liquid crystalline polymerfilm employed in another embodiment of the disclosed concept;

FIG. 5 is a schematic diagram of a portion of a transparent actuatorelement according to one particular non-limiting exemplary embodiment ofthe disclosed concept;

FIG. 6 is a schematic diagram of a display apparatus according to anexemplary embodiment of the disclosed concept;

FIG. 7 is a schematic diagram of an actuator element array according toone particular exemplary embodiment of the disclosed concept; and

FIGS. 8A and 8B are schematic diagrams of a display assembly accordingto an alternative exemplary embodiment of the disclosed concept.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

As used herein, the singular form of “a”, “an”, and “the” include pluralreferences unless the context clearly dictates otherwise.

As used herein, the statement that two or more parts or components are“coupled” shall mean that the parts are joined or operate togethereither directly or indirectly, i.e., through one or more intermediateparts or components, so long as a link occurs.

As used herein, “directly coupled” means that two elements are directlyin contact with each other.

As used herein, the statement that two or more parts or components“engage” one another shall mean that the parts exert a force against oneanother either directly or through one or more intermediate parts orcomponents.

As used herein, the term “number” shall mean one or an integer greaterthan one (i.e., a plurality).

As used herein, the term “arch-shaped” shall mean a number of curved,folded, creased or wrinkled shapes that spans a space from a first pointto a second point, and shall include both symmetrical andnon-symmetrical curved shapes.

As used herein, the term “cross linked” shall mean conversion of monomermixtures into cured, solid polymer films following exposure to heat andor light.

As used herein, the term “optically transparent” shall mean allowingtransmission of light in the part of the electromagnetic spectrum thatis visible to the human eye (typically wavelengths of light ranging from350 nm to 800 nm).

As used herein, the term “liquid crystalline polymer” shall mean a crosslinked polymer created from liquid crystalline monomers, wherein themonomers possess a mesogenic/nematic core which can developorientational order across macroscopic lengths-scales, and shallinclude, without limitation, cross linked films that have twistednematic and splayed liquid crystalline ordering.

Directional phrases used herein, such as, for example and withoutlimitation, top, bottom, left, right, upper, lower, front, back, andderivatives thereof, relate to the orientation of the elements shown inthe drawings and are not limiting upon the claims unless expresslyrecited therein.

As described in detail herein, the disclosed concept provides anoptically transparent actuator that may be structured to implement anoptically transparent display, such as a display that provides hapticfeedback and/or generated 3D structures on command. The disclosedconcept is described herein, for purposes of explanation, in connectionwith numerous specific details in order to provide a thoroughunderstanding of the disclosed subject matter. It will be evident,however, that the disclosed concept can be practiced without thesespecific details without departing from the spirit and scope of thisinnovation.

FIGS. 1A and 1B show an optically transparent actuator element 2according to an exemplary embodiment of the disclosed concept. As seenin FIGS. 1A and 1B, actuator element 2 includes a bi-stable arch member4 structured to move from a first stable state (shown in FIG. 1A) to asecond stable state (shown in FIG. 1B) in response to a first stimulusbeing applied thereto, and from the second stable state (FIG. 1B) to thefirst stable state (FIG. 1A) in response to a second stimulus beingapplied thereto. In the illustrated exemplary embodiment describedherein and shown schematically in FIGS. 1A and 1B, the first stimulusand the second stimulus take the form of heat that is selectivelyapplied to bi-stable arch member 4 by way of resistive heating (alsoknown as Joule heating or ohmic heating). In particular, as shownschematically in FIG. 1A and FIG. 1B, an electric current is passedthrough a conductor forming part of bi-stable arch member 4 to generatethe heat. In the exemplary embodiment, the required voltages are on theorder of 1V to 10V and the current loads are approximately 10 mA. Thisis very different from known dielectric actuators which require hundredsor thousands of volts to operate. In addition, in the exemplaryembodiment, the movement from the first stable state to the secondstable state and the movement from the second stable state to the firststable state is by snap-through action of the arch-shaped member.

In exemplary embodiments of the disclosed concept, described in greaterdetail elsewhere herein, a number of transparent actuator elements 2 maybe used to form a haptic or 3D pop-up display. In such implementations,each bi-stable arch member 4 is structured to: (i) not impact/engage anoptically transparent plate member when in the first state, and (ii)impact/engage the optically transparent plate member and thereby providehaptic feedback and/or a three-dimensional shape when in the secondstate. In the case of the haptic display implementation, when thetransparent actuator element 2 impacts the optically transparent platemember at the end of its snap-through, it transmits an impulse throughthe optically transparent plate member to provide haptic feedback. Inthe case of the 3-D pop-display implementation, the transparent actuatorelement to impacts the optically transparent plate member at the end ofits snap through, it deforms the optically transparent plate member toform part of a three-dimensional shape. It will be appreciated thatstill other applications of the transparent actuator element 2 arepossible within the scope of the disclosed concept.

FIG. 2 is a schematic diagram of a portion (See FIG. 1A) of transparentactuator element 2 according to the exemplary embodiment. As seen inFIG. 2, bi-stable arch member 4 is a multilayer structure. Inparticular, bi-stable arch member 4 in the illustrated exemplaryembodiment includes a bottom optically transparent conductor member 6and a top optically transparent conductor member 8. In the exemplaryembodiment, bottom optically transparent conductor member 6 and topoptically transparent conductor member 8 are both made of a transparentconductive material such as, without limitation, indium tin oxide (ITO).Alternatively, bottom optically transparent conductor member 6 and topoptically transparent conductor member 8 may be made of other opticallytransparent materials such as graphene, nanostructured transparentconductors, metallic ink-based transparent conductors or carbon nanotube(CNT) conductors. In addition, bi-stable arch member 4 includes a liquidcrystalline polymer layer 10 provided between bottom opticallytransparent conductor member 6 and top optically transparent conductormember 8.

When bi-stable arch member 4 is in a downward state as illustrated inFIG. 1B, it can be toggled to snap upward to an upward state when topoptically transparent conductor number 8 is energized and therebygenerates heat resistively. When bi-stable arch member 4 is in theupward state as illustrated in FIG. 1A, it can be toggled to snapdownward to the downward state when bottom optically transparentconductor member 6 is energized and thereby generates heat resistively.Thus, repetitive actuation of bi-stable arch member 4 is possible.

In the exemplary embodiment, liquid crystalline polymer layer 10includes a number of liquid crystalline polymer films. For example, andwithout limitation, liquid crystalline polymer layer 10 may include anumber of twisted nematic liquid crystalline polymer films 12 as shownschematically in FIG. 3, or a number of splayed liquid crystallinepolymer films 18 as shown schematically in FIG. 4.

Referring to FIG. 3, as is known in the art, twisted nematic liquidcrystalline polymer film 12 includes a top planar aligned side 14wherein the molecules are aligned in a first planar manner, and a bottomplane aligned side 16 wherein the molecules are aligned in a secondplanar manner. As illustrated in FIG. 3, the molecules are alignedorthogonally on each side. In particular, in top planar aligned side 14,the molecules are aligned along the short axis, and in bottom planaraligned side 16, the molecules are aligned along the long axis (thiscould, of course, be reversed with the molecules aligned along the shortaxis being on the bottom and molecules aligned along the long axis beingon the top). In both top planar aligned side 14 and bottom planaraligned side 16, the molecular axis is in the plane of the respectivesurface.

Referring to FIG. 4, as is known in the art, splayed liquid crystallinepolymer film 18 includes a homeotropic side 20 and a planar aligned side22. In homeotropic side 20, the molecules are aligned vertically(homeotropically), while in planar aligned side 22, the molecules arealigned in a planar manner in the plane of the surface. Morespecifically, as seen in FIG. 4, in homeotropic side 20, the moleculesare perpendicular to the surface of homeotropic side 20, and in planaraligned side 22, the molecules are aligned along the long axis(alternatively, the molecules could be aligned along the short axis).

FIG. 5 is a schematic diagram of a portion (See FIG. 1A) of transparentactuator element 2 according to one particular, non-limiting exemplaryembodiment. As seen in FIG. 5, liquid crystalline polymer layer 10includes two cross-linked films that are bonded to one another. Forexample, the two cross-linked films may be two cross-linked twistednematic liquid crystalline polymer films 12 as shown in FIG. 3 or twocross-linked splayed liquid crystalline polymer films 18 as shown inFIG. 4. In one particular implementation, the two cross-linked films aretwo cross-linked twisted nematic liquid crystalline polymer films 12having the top planar aligned sides 14 thereof bonded together face toface. In another particular implementation, the two cross-linked filmsare two splayed liquid crystalline polymer films 18 having thehomeotropic sides 20 thereof bonded together face-to-face. In thisparticular exemplary embodiment, it is desirable to use a right-handedchiral dopant, which ensures the same sense of rotation of the directorthrough the thickness in each film.

In an another particular implementation, liquid crystalline polymerlayer 10 comprises an integral sample that has a supertwisted nematicconfiguration. In this configuration, liquid crystalline polymer layer10 comprises an integral film where the nematic director undergoes acomplete period of rotation through the thickness. This configurationwill function essentially the same as the bonded configuration describedabove, but it can be a single integral film instead of making two andbonding them face to face as described.

In addition, in the exemplary embodiment, each film of liquidcrystalline polymer layer 10 is on the order of 10 μm to 500 μm inthickness. Also, the optically transparent conductor members 6 and 8 areeach on the order of tens of nanometers in thickness.

According to one non-limiting, exemplary embodiment, a plurality ofbi-stable arch members 4 as shown in FIG. 5 may be formed in thefollowing manner. First, a mixture comprising an acrylate-functionalizedmesogen with trace amounts of chiral dopant and trace amounts ofIrgacure 784 is capillary filled in patterned glass cells to create asheet of material. A plurality of strips each forming an individualliquid crystalline polymer films 12 and/or 18 are then be created byexcising such strips from the sheet of material. The harvested stripsare then adhered together (e.g., glued together) with suitableorientations as described herein to create the sandwich structure ofliquid crystalline polymer layer 10 shown in FIG. 5. Thereafter, asuitable deposition technique, such as RF magnetron sputtering, e-beamdeposition, atomic layer deposition or transfer printing, is be used todeposit bottom optically transparent conductor member 6 and topoptically transparent conductor member 8 (e.g., made from ITO, graphene,CNT, nanowire arrays, nanomesh structures) onto each side of the stripsas shown in FIG. 5. Next, the strip-shaped (non-arched) samples as justformed are held at the terminal ends thereof (e.g., by being mounted inrigid supports), and a displacement force is applied at each end(inwardly toward the center) to create an arch-shape (bi-stable) bybuckling.

FIG. 6 is a schematic diagram of a display apparatus 24 according toanother exemplary embodiment of the disclosed concept. In theillustrated exemplary embodiment, display apparatus 24 is a hapticdisplay apparatus that provides location sensitive haptic feedback usingtransparent actuator elements 2 as described herein.

In particular, as seen in FIG. 6, display apparatus 24 includes adisplay assembly 26 that is coupled to an electronic control system 28.Display assembly 26 includes an actuator element array 30 that isoperatively coupled to an optically transparent plate member 32.Actuator element array 30 according to one particular exemplaryembodiment is shown in FIG. 7. As seen in FIG. 7, actuator element array30 includes a plurality of transparent actuator elements 2 arranged inan array pattern including a plurality of rows and a plurality ofcolumns. In the illustrated exemplary embodiment, three rows and fourcolumns are shown. It will be understood, however, that that is meant tobe exemplary only, and that more or less rows and/or columns may beemployed within the scope of the disclosed concept. Each transparentactuator element 2 in actuator element array 30 is individuallyaddressable/accessible by way of wire (conductor) members 34 and wire(conductor) members 36. In this manner, electrical current may beselectively and individually provided to the bottom opticallytransparent conductor members 6 and the top optically transparentconductor members 8 of the individually actuator elements 2 as desiredin order to actuate each individual transparent actuator element 2 inthe manner described herein. In the exemplary embodiment, wire members34 are coupled to the bottom optically transparent conductor members 6and wire members 36 are coupled to the top optically transparentconductor members 8.

Optically transparent plate member 32 is, in the exemplary embodiment, aglass, ceramic, or polymer plate. When any transparent actuator element2 is actuated and thereby impacts optically transparent plate member 32at the end of its snap-through, it transmits an impulse throughoptically transparent plate member 32 to provide haptic feedback.

Display assembly 26 is operatively coupled to and controlled byelectronic control system 28. Electronic control system 28 includes acontroller 38, a resistive heating module 40, and a power supply 42.Controller 38 may be any suitable processing device such as, withoutlimitation, a microprocessor, a microcontroller, or an applicationspecific integrated circuit. Resistive heating module 40 is structuredand configured to provide a low current (on the order of tens of mA)with a low voltage (on the order of 1V to 10V) selectively to one ormore of the wire members 34 and/or 36 as desired in order to selectivelycontrol the actuation of the bi-stable arch members 6 of the transparentactuator elements 2 between the first and second states thereof asdescribed herein. Thus, as just described, display apparatus 24 providesa display surface that is able to provide location sensitive hapticfeedback.

In an alternative embodiment, display apparatus 24 may be provided witha deformable/morphable display surface which can be made to deform usinglow-power as described herein. In particular, in such an implementation,optically transparent plate member 32 would be made of a deformabletransparent material such as, without limitation, a liquid crystallinepolymer or a shape memory polymer, among others, either as integralfilms or those attached or suspended on a suitable substrate. In such aconfiguration, actuation of the transparent actuator elements 2 asdescribed herein would cause selected portions of the deformableoptically transparent plate member 32 to be deformed so as to project3-D shapes on command. In such an implementation, display apparatus 24may be used to provide a 3D pop-up display for use on a device such as,without limitation, a hand-held device like a smartphone.

FIGS. 8A and 8B are schematic diagrams of a display assembly 40according to an alternative exemplary embodiment that may be coupled toan electronic control system such as electronic control system 28 shownin FIG. 6. As described in detail below, display assembly 40 includes acontinuous liquid crystalline polymer film structure on which electrodesare provided. The electrodes are structured to be powered in pairs,which powering would cause a portion of the continuous liquidcrystalline polymer film structure to wrinkle and thereby create rippleswhich may be used to provide haptic feedback and/or generatethree-dimensional shape as described herein. In particular, referring toFIG. 8A, display assembly 40 includes a substrate 42 and a liquidcrystalline polymer film structure 44 provided on a top surface ofsubstrate 42. Substrate 42 may be, for example without limitation, agel, a soft oligomer, a soft polymer like polydimethylsiloxane (PDMS),or simply air. Liquid crystalline polymer film structure 44 includes aliquid crystalline polymer film layer 45 that is similar to liquidcrystalline polymer film 10 described herein (which may include a numberof twisted nematic liquid crystalline polymer films 12 as shownschematically in FIG. 3, or a number of splayed liquid crystallinepolymer films 18 as shown schematically in FIG. 4) and one or moreoptically transparent conductor layers 47 (similar to opticallytransparent conductor members 6 and 8 described herein) coupled to theliquid crystalline polymer film layer 45. As seen in FIG. 8A, aplurality of conductive electrodes 46 are provided on the top surface ofliquid crystalline polymer film structure 44. In the exemplaryembodiment, each electrode 46 is a transparent conductor as describedelsewhere herein and is electrically coupled to optically transparentconductive layer 47. In addition, each electrode 46, labeled 1-6 andA-F, is coupled to a resistive heating module such as resistive heatingmodule 40 of electronic control system 28, by an associated conductor 48which allows current to be selectively and individually provided to eachelectrode 46.

In operation, when current is applied between pairs of electrodes 46,the region of liquid crystalline polymer film structure 44 between thepairs of electrodes 46 is heated by the current, which actuates liquidcrystalline polymer film structure 44 (e.g., the twisted nematic or thesplayed liquid crystalline polymer of liquid crystalline polymer filmlayer 45). This is shown, for example, in FIG. 8B, wherein current isapplied to the electrodes 46 labeled 2 and E, which results in ripples50 being provided in the region between those two electrodes. The reasonliquid crystal polymer film structure 44 wrinkles is due to a bucklingtransition that is very similar to what occurs in actuator elements 2described elsewhere herein. Basically, if a thin liquid crystallinepolymer film, like that in liquid crystalline polymer film structure 44,is subjected to compressive strains, here generated using electricheating, it will buckle. If the film is a continuous film, like that inliquid crystalline polymer film structure 44, the buckling will resultin a wrinkled/rippled pattern. When the current is turned off, the filmrelaxes, the strains are removed and the buckled pattern goes away. Inone particular embodiment, an optically transparent plate member 32 asshown in FIG. 6 is provided on top of liquid crystalline polymer film 44and electrodes 46.

In the claims, any reference signs placed between parentheses shall notbe construed as limiting the claim. The word “comprising” or “including”does not exclude the presence of elements or steps other than thoselisted in a claim. In a device claim enumerating several means, severalof these means may be embodied by one and the same item of hardware. Theword “a” or “an” preceding an element does not exclude the presence of aplurality of such elements. In any device claim enumerating severalmeans, several of these means may be embodied by one and the same itemof hardware. The mere fact that certain elements are recited in mutuallydifferent dependent claims does not indicate that these elements cannotbe used in combination.

Although the invention has been described in detail for the purpose ofillustration based on what is currently considered to be the mostpractical and preferred embodiments, it is to be understood that suchdetail is solely for that purpose and that the invention is not limitedto the disclosed embodiments, but, on the contrary, is intended to covermodifications and equivalent arrangements that are within the spirit andscope of the appended claims. For example, it is to be understood thatthe present invention contemplates that, to the extent possible, one ormore features of any embodiment can be combined with one or morefeatures of any other embodiment.

What is claimed is:
 1. An optically transparent actuator apparatus,comprising: an optically transparent bi-stable member including anoptically transparent liquid crystalline polymer layer, wherein thebi-stable member is structured to move from a first state to a secondstate in response to a first stimulus and from the second state to thefirst state in response to a second stimulus, wherein the bi-stablemember has an arch-shaped portion, wherein the first state is a firstarched state and the second state is a second arched state opposite thefirst arched state, and wherein the movement from the first state to thesecond state and the movement from the second state to the first stateis each by snap-through action so as to provide haptic feedback.
 2. Theactuator apparatus according to claim 1, wherein the liquid crystallinepolymer layer comprises a number of twisted nematic liquid crystallinepolymer films.
 3. The actuator apparatus according to claim 2, whereinthe liquid crystalline polymer layer comprises a pair of cross-linkedtwisted nematic liquid crystalline polymer films.
 4. The actuatorapparatus according to claim 1, wherein the liquid crystalline polymerlayer comprises a number of splayed liquid crystalline polymer films. 5.The actuator apparatus according to claim 4, wherein the liquidcrystalline polymer layer comprises a pair of cross-linked splayedliquid crystalline polymer films.
 6. The actuator apparatus according toclaim 1, wherein the bi-stable member comprises a layered structureincluding: (i) a first transparent conductor layer, (ii) a secondtransparent conductor layer, and (iii) the liquid crystalline polymerlayer, wherein the liquid crystalline polymer layer is provided inbetween the first transparent conductor and the second transparentconductor.
 7. The actuator apparatus according to claim 6, wherein thefirst transparent conductor and the second transparent conductor areeach an indium tin oxide transparent conductor, a graphene transparentconductor, a nanostructured transparent conductor, a metallic ink-basedtransparent conductor, or a carbon nanotube transparent conductor. 8.The actuator apparatus according to claim 1, wherein the first stimulusand the second stimulus are each heat.
 9. A method of controlling anactuator in a display apparatus to provide haptic feedback, comprising:providing a first stimulus to an optically transparent bi-stable memberincluding an optically transparent liquid crystalline polymer layer tocause the bi-stable member to move from a first state to a second state;and providing a second stimulus to the bi-stable member to cause thebi-stable member to move from the second state to the first state,wherein the bi-stable member has an arch-shaped portion, wherein thefirst state is a first arched state and the second state is a secondarched state opposite the first arched state, and wherein the movementfrom the first state to the second state and the movement from thesecond state to the first date is each by snap-through action.
 10. Themethod according to claim 9, wherein the first stimulus and the secondstimulus are each heat.
 11. The actuator apparatus according to claim 1,wherein the liquid crystalline polymer layer comprises a first sidewherein the molecules in the first side are aligned in a first manner,and a second side wherein the molecules in the second side are alignedin a second manner that is orthogonal to the first manner.
 12. Theactuator apparatus according to claim 11, wherein first side is a firstplanar aligned side wherein the molecules in the first planar alignedside are aligned in a first planar manner, and wherein the second sideis a second planar aligned side wherein the molecules in the secondplanar aligned side are aligned in a second planar manner that isorthogonal to the first planar manner.
 13. The actuator apparatusaccording to claim 12, wherein the molecules in the first planar alignedside are aligned along a first axis of the optically transparentbi-stable member and the molecules in the second planar aligned side arealigned along a second axis of the optically transparent bi-stablemember that is orthogonal to the first axis.
 14. The actuator apparatusaccording to claim 13, wherein the first axis is a short axis of theoptically transparent bi-stable member and the second axis is a longaxis of the optically transparent bi-stable member.
 15. The actuatorapparatus according to claim 11, wherein first side is a first planaraligned side wherein the molecules in the first planar aligned side arealigned in a first planar manner, and wherein the molecules in thesecond side are aligned homeotropically.
 16. The method according toclaim 9, wherein the liquid crystalline polymer layer comprises a firstside wherein the molecules in the first side are aligned in a firstmanner, and a second side wherein the molecules in the second side arealigned in a second manner that is orthogonal to the first manner. 17.The method according to claim 16, wherein the first side is a firstplanar aligned side wherein the molecules in the first planar alignedside are aligned in a first planar manner, and wherein the second sideis a second planar aligned side wherein the molecules in the secondplanar aligned side are aligned in a second planar manner that isorthogonal to the first planar manner.
 18. The method according to claim17, wherein the molecules in the first planar aligned side are alignedalong a first axis of the optically transparent bi-stable member and themolecules in the second planar aligned side are aligned along a secondaxis of the optically transparent bi-stable member that is orthogonal tothe first axis.
 19. The method according to claim 18, wherein the firstaxis is a short axis of the optically transparent bi-stable member andthe second axis is a long axis of the optically transparent bi-stablemember.
 20. The method according to claim 16, wherein the first side isa first planar aligned side wherein the molecules in the first planaraligned side are aligned in a first planar manner, and wherein themolecules in the second side are aligned homeotropically.